This invention relates to N-phenylpyrazole derivatives, to compositions containing them and to the use of N-phenylpyrazole derivatives against arthropod, plant nematode, helminth and protozoan pests.
In J. Heter, Chem., 12 (1975) 1199-1205, P. L. Southwick and B. Dhawan have described experiments for the preparation of 4,6-diamino-pyrazolo3,4-d!pyrimidines in the expectation that such pyrimidine derivatives would have useful pharmacological properties. They employed as starting materials 5-amino-4-cyanopyrazoles carrying on the 1-position a hydrogen atom, a methyl group, a hydroxyethyl group or a phenyl group substituted by one or more chlorine atoms and/or methyl groups, and on the 3-position a hydrogen atom, a methyl group or a phenyl or benzyl group. This publication contains no suggestion that compounds of general formula I possess or would be expected to possess activity against arthropods, helminths or plant nematodes.
Apparently these pyrazole compounds did not lead (according to the authors of the article) to useful therapeutic (viz. antimalarial) 4,6-diaminopyrazolo3,4-d!pyrimidines.
U.S. Pat. No. 3,760,084 describes certain 5-amino-1-phenyl-pyrazoles as being useful far ameliorating inflammation in warm-blooded animals: the compounds carry on the 3-position hydrogen or a lower alkyl group and on the 4-position a carbamoyl or cyano group.
U.S. Pat. No. 3,869,274 describes certain 4-nitropyrazoles as being useful for the induction of abscission of fruit from fruit-bearing plants.
U.S. Pat. No. 4,066,776 describes a very extensive group of 1,4-disubstituted-3-nitropyrazoles as having antimicrobial, parasiticidal and herbicidal properties: the great biological activity of the compounds is stated to be limited to the 3-nitropyrazoles disclosed, the characterizing feature of the compounds being the 3-nitropyrazole nucleus.
Japanese Patent Publication No. 12644/64 describes a process for the preparation of 4-thiocyanatopyrazole derivatives which are stated to be useful as germicides.
Japanese Patent Publication No. 49-117502 describes certain pyrazole sulphonamides having anti-thrombogenic properties.
None of the foregoing publications describes or suggests that compounds of general formula I possess or would be expected to possess the activity against arthropods, helminths or plant nematodes which has been discovered by the inventors.